The all-singing, all-dancing media player VLC has reached version 1.0.0 at long last. This free, open source, cross platform media player removes the headache of trying to play almost any sort of video, offering built-in support for most video formats - so you're not stuck trying to find some ridiculous obscure codec for some random video you downloaded.
It comes highly recommended, not just because it is free and open source, but because it is a genuinely useful application that is definitely worth your time.
You can download it now locally from AusGamers in both Windows
and Mac OS X